EP-4737011-A2 - CABIN AIR FILTER SYSTEM FOR A VEHICLE AND METHOD FOR CLEANING AIR TO BE SUPPLIED TO A CABIN

EP4737011A2EP 4737011 A2EP4737011 A2EP 4737011A2EP-4737011-A2

Abstract

The present invention relates to a cabin air filter system (100) for a vehicle, comprising at least one particle filter element (5) and a cyclone separator (2) positioned upstream of the at least one particle filter element (5). The cabin air filter system (100) comprises a particle agglomeration device (1) positioned upstream of the cyclone separator (2). According to a second aspect the present invention relates to a method for cleaning air to be supplied to a cabin, in particular a cabin of a vehicle, with a cabin air filter system.

Inventors

MÜNKEL, Karlheinz
Bauch, Maximilian
NARDINI, David
Schön, Mirco
WOITOLL, INA
SIEGELE, THOMAS
ZERILLI, Matthew
KUNZE, STEFAN
LARDEUX, Sebastien
Krautner, Christoph

Assignees

MANN+HUMMEL GmbH

Dates

Publication Date: 20260506
Application Date: 20220413

Claims (15)

Cabin air filter system (100) for a vehicle, comprising at least one particle filter element (5) and a cyclone separator (2) positioned upstream of the at least one particle filter element (5), characterized in that the cabin air filter system (100) comprises a particle agglomeration device (1) positioned upstream of the cyclone separator (2).
Cabin air filter system (100) according to claim 1, characterized in that the particle agglomeration device (1) comprises at least one of: A mono-polar ionizer, a bi-polar ionizer, an electrostatic discharge device, a sound source, in particular ultrasound source, a humidification device, a magnetic-effect device.
Cabin air filter system (100) according to claim 1 or 2, characterized in that the particle agglomeration device (1) is adapted to effect an increase of an effective diameter of at least a portion of a totality of particles contained in a raw air flow to be processed by the particle agglomeration device (1).
Cabin air filter system (100) according to any of the claims 1 to 3, characterized in that the cabin air filter system (100) comprises a bypass duct (10) around the at least one particle filter element (5) and a flap (4) that is adapted to switch the bypass duct (10), wherein in a filtration mode an air flow is processed by the at least one particle filter element (5) and in a bypass mode an air flow is bypassed through the bypass duct (10).
Cabin air filter system (100) according to any of the preceding claims, characterized in that the particle filter element (5) is a HEPA filter element, in particular a HEPA filter element that fulfils specification H13 according to EN 1822 or better.
Cabin air filter system (100) according to any of the preceding claims, characterized in that the cabin air filter system (100) comprises an airstream generation device (6), in particular a blower (6), wherein the blower (6) is in particular positioned downstream of the particle filter element (5).
Cabin air filter system (100) according to any of the preceding claims, characterized in that the cabin air filter system (100) comprises an adsorption filter element (8) that is spatially separated from the particle filter element (5), wherein the adsorption filter element (8) is in particular positioned downstream of the airstream generation device (6).
Cabin air filter system (100) according to any of the preceding claims, characterized in that the cabin air filter system comprises (100) - an outside air inlet (11) that is adapted to receive outside air, wherein the outside air inlet (11) is positioned upstream of the particle agglomeration device (1) and/or - a cabin air outlet (12) that is adapted to feed an air flow processed by the cabin air filter system (100) to a cabin, wherein the cabin air outlet (12) is in particular positioned downstream of the adsorption filter element (8).
Cabin air filter system (100) according to any of the preceding claims, characterized in that the cabin air filter system (100) comprises an alternative inlet (13), in particular a recirculation inlet, that is adapted to receive air from the cabin, wherein the alternative inlet (13) is in particular positioned downstream of the cyclone separator (2) and upstream of the at least one particle filter element (5).
Cabin air filter system (100) according to claim 9, characterized in that the cabin air filter system (100) comprises an inlet selection flap (3) that is adapted to selectively switch the alternative inlet (13).
Cabin air filter system (100) according to any of the claims 7 to 10, characterized in that the cabin air filter system (100) comprises at least one heating element (7) adapted for heating the adsorption filter element (8) for regeneration, wherein the heating element (7) comprises at least one of: A resistance heater, a PTC heater, a heat exchanger for a heat transfer medium.
Cabin air filter system (100) according to claim 11, characterized in that the heating element (7) is thermally conductively coupled to the adsorption filter element (8) or positioned upstream of the adsorption filter element (8) so as to heat a regeneration air flow to be processed by the adsorption filter element (8).
Cabin air filter system (100) according to claim 11 or 12, characterized in that the cabin air filter system (100) comprises a regeneration flap (9), wherein the regeneration flap (9) is adapted to switch a regeneration outlet (91) to the environment, wherein the regeneration flap (9) is in particular positioned downstream of the adsorption filter element (8).
Cabin air filter system (100) according to claim 11 or 13, characterized in that the cabin air filter system (100) is shiftable into a regeneration mode in that the adsorption filter element (8) is regenerated, wherein in the regeneration mode: - the heating element (7) is activated so that the adsorption filter element (8) is heatable to a temperature above a predefined regeneration temperature and - the regeneration outlet (91) is opened by the regeneration flap (9) so that the regeneration air flow processed by the adsorption filter element (8) is releasable to the environment.
Method for cleaning air to be supplied to a cabin, in particular a cabin of a vehicle, with a cabin air filter system, in particular a cabin air filter system (100) according to any of the preceding claims, wherein the cabin air filter system (100) comprises at least one particle filter element (5), a cyclone separator (2) positioned upstream of the at least one particle filter element (5) and a particle agglomeration device (1) positioned upstream of the cyclone separator (2), the method comprising the steps: - processing a raw air flow received from the outside in the particle agglomeration device (1), thereby increasing an effective diameter of at least a portion of a totality of particles contained in the raw air flow, - processing an air flow processed by the particle agglomeration device (1) in the cyclone separator (2), thereby by inertial action removing at least a portion of a totality of particles contained in the air flow processed by the particle agglomeration device (1) in the cyclone separator (2), - processing an air flow processed by the cyclone separator (2) in the particle filter element (5), thereby removing at least a portion of a totality of particles contained in the air flow processed by the cyclone separator (2) in the particle filter element (5), - supplying the air flow processed by the particle filter element (5) to the cabin.

Description

Technical field The present invention relates to a cabin air filter system for a vehicle and a method for cleaning air to be supplied to a cabin, in particular a cabin of a vehicle, in particular of a motor vehicle. Prior art Vehicular cabin air filter systems have been known for a long time. Those systems typically include at least one particle filter element that comprises a porous particle filtration media adapted to remove at least a portion of the particles contained in a raw air flow. The raw air flow can either originate from the outside environment or from the cabin itself, wherein the latter first of all applies to a recirculation mode of the cabin air filter system. Typical particle filter elements are to be replaced as soon as their dust holding capacity is reached which is usually done in predefined service intervals, e.g. annually or after a certain number of driven kilometers. Over the lifetime of a vehicle the regular replacement of cabin air filter elements can be considered a significant maintenance effort and a sustainability issue as the used filter elements are typically scrapped, e.g. by thermal processing. In the prior art there are approaches to prolong the lifetime of cabin air filter elements by applying pre-separation with wear-free separation devices so that only a fraction of a totality of particles contained in the raw air reaches the particle filter element. Some instances of such systems are known from WO 2006/099852 A1 and WO 2005/118149 A1 for example that combine a conventional particle filter element with a cyclone pre-separator positioned upstream of the particle filter element. Although the implementation of a cyclone pre-separator has a certain impact on the lifetime of the particle filter element it cannot be considered sufficient. The downside of such systems is that cyclone separators have an efficiency that strongly depends on the particle diameter. While cyclones can exhibit relatively high separation rates in the range of 70% or even more with particles having a diameter above approximately 5µm their separation efficiency is rather poor with smaller particles. This is to say that the approaches disclosed in the prior art may be a functional solution for the fraction of larger particles however do not provide a significant pre-separation for the fraction of smaller particles. In the systems described in the prior art these smaller particles with a diameter below approximately 5µm still have to be almost completely separated by the particle filter element. This especially is especially challenging as both end customers and vehicle OEMs are having increasing interest in cabin air quality and a general industrial trend towards HEPA-filtration can be observed. The smallest fraction of particles contained in the ambient air that is considered to be most detrimental to the human health and that contributes with a major share to the loading of fine particle filtration elements, especially of HEPA elements, practically is not removable at all by the cyclones of the systems described in the prior art. So, simply combining a HEPA filter element with a cyclone pre-separator would not lead to a significant pre-separation in the smallest particle fraction and thus not lead to an increased lifetime of the HEPA filter element. Summary of the invention In the view of the above it is therefore an object of the invention to provide a cabin air filter system that has a significantly increased service life of a particle filter element used therein. This object is solved by a cabin air filter system with the features of independent claim 1. According to a first aspect of the invention the cabin air filter system for a vehicle comprises at least one particle filter element and a cyclone separator positioned upstream of the at least one particle filter element. The cabin air filter system further comprises a particle agglomeration device positioned upstream of the cyclone separator. The effect of the particle agglomeration device is that it increases an effective diameter of at least a portion of a totality of particles contained in a raw air. In other words, the particle agglomeration device effects a displacement of the particle spectrum to larger particle sizes. This has the advantage that the fraction of larger particles that can be removed with the cyclone separator is increased and by that the amount of particles that has to be removed with the particle filter element is minimized. This results in a significantly increased service life of the filter element. In some instances of the invention the service life of the particle filter element can be increased in a way that replacement is only necessary after 7 or even more years or after several 100.000 kilometers driven. The cyclone separator can comprise at least one cyclone cell, in particular an axial cyclone cell. In embodiments the cyclone separator can comprise a multitude of axial cyclone cells arranged together in an axial mu